Dial pulse detector and detecting method for paging service for mechanical telephone subscriber

Abstract

A dial pulse detector in a paging system for rendering a paging service for a subscriber who uses a mechanical telephone includes a delay correlativity calculator for receiving dial pulses generated by predetermined pre-test dialing digits dialed by the subscriber, calculating the correlativity between the delayed dial pulse and undelayed dial pulse to sample a reference signal of the dial pulse. An energy correlativity calculator calculates the energy correlativity between the sampled reference signal and the successively received dial pulse to examine the validity of the reference signal. A dial pulse verifier operates according to recognition of the validity of the reference signal by the energy correlativity calculator and checks input number of times and input time of the dial pulse so as to verify whether the dial pulse corresponds to the pre-test dialing digits.

What is claimed is: 
     
       1. A dial pulse detector in a paging system for rendering a paging service for a subscriber using a mechanical telephone, comprising: a pre-processor filtering dial pulses generated by predetermined pre-test dialing digits dialed by a mechanical telephone subscriber with a dial pulse band and samples only the dial pulse for each predetermined cycle among said filtered dial pulses, said pre-processor comprising a low-pass, finite impulse response filter filtering a band of a dial pulse signal, said low-pass filter removing noise contained in the dial pulses, and   a sample sampling only each kth dial pulse among said filtered dial pulses;     a delay correlativity calculator receiving dial pulses generated by predetermined pre-test dialing digits dialed by said subscriber, calculating the correlativity between a delayed dial pulse and an undelayed dial pulse to sample a reference signal of said dial pulse, delay correlativity calculator comprising a dial pulse delayer delaying applied dial pulses at a predetermined velocity, said dial pulse delayer having a first-in-first-out type buffer;   a first calculator receiving a first predetermined number of samples r ! among said dial pulses which are not delayed, and performing calculation in the following equation (1) to output a result value γ1;   a second calculator receiving a second predetermined number of samples s ! among said dial pulses which are delayed by a first predetermined delay period, and performing calculation in the following equation (2) to output a result value γ2;   a third calculator receiving said samples r ! and s ! and performing calculation in the following equation (3) to output a result value C 0  ; and   a delay correlativity determiner receiving said result values γ1, γ2 and C 0  and determining the delay correlativity of said dial pulse using the following relationship set forth in equation (4): ##EQU13## an energy correlativity calculator calculating an energy correlativity between said sampled reference signal and a received dial pulse to examine validity of said reference signal, said energy correlativity calculator comprising:   a first buffer temporarily storing a third predetermined number of samples r' ! among successively applied dial pulses;   a second buffer temporarily storing a fourth predetermined number of said samples s ! among said sampled reference signals;   a first calculator receiving said samples r' !, and performing calculation in the following equation (5) to output a result value γ a  ;   a second calculator receiving said samples s !, and performing calculation in the following equation (6) to output a result value γ b  ;   a third calculator receiving said samples r ! and s !, and performing calculation in the following equation (7) to output a result value C 1  ; and   an energy correlativity determiner receiving said result values γ a , γ b  and C 1  ; and determining the energy correlativity using the following relationship (8): ##EQU14## a dial pulse verifier operating according to recognition of the validity of said reference signal by said energy correlativity calculator and checking number of times that have been input and time of input of said dial pule, said dial pulse verifying whether said dial pulse corresponds to said pre-test dialing digits.     
     
     
       2. A dial pulse detector comprising: a delay correlativity calculator for receiving dial pulses generated by predetermined pre-test dialing digits dialed by a subscriber, and including a delay section for delaying a dial pulse to produce a delayed dial pulse, said delay correlativity calculator calculating a correlativity between the delayed dial pulse and an undelayed dial pulse to sample a reference signal of said dial pulse and obtain a sampled reference signal;   an energy correlativity calculator for calculating an energy correlativity between said sampled reference signal and a received dial pulse, said energy correlativity calculator examining validity of said reference signal; and   a dial pulse verifier operating according to a recognition of the validity of said reference signal by said energy correlativity calculator, for checking input number of times and input time of said dial pulse, and for verifying whether said dial pulse corresponds to said pre-test dialing digits.   
     
     
       3. The dial pulse detector of claim 2, wherein the dial pulse detector further comprises: a pre-processor filtering dial pulses generated by said predetermined pre-test dialing digits dialed by said subscriber, using a dial pulse band, and sampling only a selected dial pulse for each predetermined cycle among said filtered dial pulses.   
     
     
       4. The dial pulse detector as claimed in claim 3, wherein said pre-processor comprises: a filter filtering a band of a dial pulse signal; and   a sampler sampling only each kth dial pulse among said filtered dial pulses.   
     
     
       5. The dial pulse detector as claimed in claim 4, wherein said filter is a low-pass filter suitable for removing noise contained in each dial pulse. 
     
     
       6. The dial pulse detector as claimed in claim 5, wherein said low-pass filter is a finite impulse response filter. 
     
     
       7. The dial pulse detector of claim 2, wherein said energy correlativity calculator comprises a plurality of multipliers for multiplying received dial pulses by sampled reference signals to obtain products, and a summer for summing the products. 
     
     
       8. A dial pulse detector, comprising: a delay correlativity calculator receiving dial pulses generated by predetermined pre-test dialing digits dialed by a subscriber, and calculating a correlativity between a delayed dial pulse and an undelayed dial pulse to sample a reference signal of said dial pulse;   an energy correlativity calculator calculating an energy correlativity between said sampled reference signal and a received dial pulse, said energy correlativity calculator examining validity of said reference signal; and   a dial pulse verifier operating according to a recognition of the validity of said reference signal by said energy correlativity calculator, checking input number of times and input time of said dial pulse, and verifying whether said dial pulse corresponds to said pre-test dialing digits;   wherein said delay correlativity calculator comprises: a dial pulse delayer delaying applied dial pulses at a predetermined velocity;   a first calculator receiving a first predetermined number of samples r ! among said dial pulses which are not delayed and performing calculation in the following equation (1) to output a result value γ1;   a second calculator receiving a second predetermined number of samples s ! among said dial pulses delayed by a first predetermined delay period and performing calculation in the following equation (2) to output a result value γ2;   a third calculator receiving said samples r ! and s ! and performing calculation in the following equation (3) to output a result value C 0  ; and   a delay correlativity determiner receiving said result values γ1, γ2 and C 0  and determining the delay correlativity of said dial pulse using the following relationship (4): ##EQU15##     
     
     
       9. A dial pulse detector as claimed in claim 8, wherein said dial pulse delayer is a first-in-first-out (FIFO) type buffer. 
     
     
       10. A dial pulse detector, comprising: a delay correlativity calculator receiving dial pulses generated by predetermined pre-test dialing digits dialed by a subscriber, calculating a correlativity between a delayed dial pulse and an undelayed dial pulse to sample a reference signal of said dial pulse;   an energy correlativity calculator calculating an energy correlativity between said sampled reference signal and a received dial pulse, said energy correlativity calculator examining validity of said reference signal; and   a dial pulse verifier operating according to a recognition of the validity of said reference signal by said energy correlativity calculator, checking input number of times and input time of said dial pulse, and verifying whether said dial pulse corresponds to said pre-test dialing digits;   wherein said energy correlativity calculator comprises: a first buffer temporarily storing a first predetermined number of samples r' ! among successively applied dial pulses;   a second buffer temporarily storing a second predetermined number of samples s ! among said sampled reference signals;   a first calculator receiving said samples r' ! and performing calculation in the following equation (5) to output a result value γ a  ;   a second calculator receiving said samples s ! and performing calculation in the following equation (6) to output a result value γ b  ;   a third calculator receiving said samples r ! and s ! and performing calculation in the following equation (7) to output a result value C 1  ; and   an energy correlativity determiner receiving said result values γ a , γ b  and C 1  and determining the energy correlativity using the following relationship (8): ##EQU16##     
     
     
       11. The dial pulse detector of claim 10, wherein said energy correlator generates a clear signal when condition of equation (8) is met. 
     
     
       12. A dial pulse detector, comprising: a delay correlativity calculator receiving dial pulses generated by predetermined pre-test dialing digits dialed by a subscriber, and calculating a correlativity between a delayed dial pulse and an undelayed dial pulse to sample a reference signal of said dial pulse;   an energy correlativity calculator calculating an energy correlativity between said sampled reference signal and a received dial pulse, said energy correlativity calculator examining validity of said reference signal; and   a dial pulse verifier operating according to a recognition of the validity of said reference signal by said energy correlativity calculator, checking input number of times and input time of said dial pulse, and verifying whether said dial pulse corresponds to said pre-test dialing digits;   wherein the dial pulse detector further comprises a pre-processor filtering dial pulses generated by said predetermined pre-test dialing digits dialed by said subscriber, using a dial pulse band, and sampling only a selected dial pulse for each predetermined cycle among said filtered dial pulses;   wherein said delay correlativity calculator comprises: a dial pulse delayer delaying applied dial pulses at a predetermined velocity;   a first calculator receiving a first predetermined number of samples r ! among said dial pulses which are not delayed, and performing calculation in the following equation (1) to output a result value γ1;   a second calculator receiving a second predetermined number of samples s ! among said dial pulses delayed by a predetermined delay period, and performing calculation in the following equation (2) to output a result value γ2;   a third calculator receiving said samples r ! and s ! and performing calculation in the following equation (3) to output a result value C 0  ; and   a delay correlativity determiner receiving said result values γ1, γ2 and C 0  and determining the delay correlativity of said dial pulse using the following relationship (4): ##EQU17##     
     
     
       13. A dial pulse detector, comprising: a delay correlativity calculator receiving dial pulses generated by predetermined pre-test dialing digits dialed by a subscriber, and calculating a correlativity between a delayed dial pulse and an undelayed dial pulse to sample a reference signal of said dial pulse;   an energy correlativity calculator calculating an energy correlativity between said sampled reference signal and a received dial pulse, said energy correlativity calculator examining validity of said reference signal; and   a dial pulse verifier operating according to a recognition of the validity of said reference signal by said energy correlativity calculator, checking input number of times and input time of said dial pulse, and verifying whether said dial pulse corresponds to said pre-test dialing digits;   wherein the dial pulse detector further comprises a pre-processor filtering dial pulses generated by said predetermined pre-test dialing digits dialed by said subscriber, using a dial pulse band, and sampling only a selected dial pulse for each predetermined cycle among said filtered dial pulses;   wherein said energy correlativity calculator comprises: a first buffer temporarily storing a first predetermined number of samples r' ! among successively applied dial pulses;   a second buffer temporarily storing a second predetermined number of samples s ! among said sampled reference signals;   a first calculator receiving said samples r' ! and performing calculation in the following equation (5) to output a result value γ a  ;   a second calculator receiving said samples s !, and performing calculation in the following equation (6) to output a result value γ b  ;   a third calculator receiving said samples r ! and s ! and performing calculation in the following equation (7) to output a result value C 1  ; and   energy correlativity determiner receiving said result values γ a , γ b  and C 1  and determining the energy correlativity using the following relationship (8): ##EQU18##     
     
     
       14. The dial pulse detector of claim 13, wherein said energy correlator generates a clear signal when condition of equation (8) is met. 
     
     
       15. A dial pulse detector, comprising: a delay correlativity calculator receiving dial pulses generated by predetermined pre-test dialing digits dialed by a subscriber, and calculating a correlativity between a delayed dial pulse and an undelayed dial pulse to sample a reference signal of said dial pulse;   an energy correlativity calculator calculating an energy correlativity between said sampled reference signal and a received dial pulse, said energy correlativity calculator examining validity of said reference signal; and   a dial pulse verifier operating according to a recognition of the validity of said reference signal by said energy correlativity calculator, checking input number of times and input time of said dial pulse, and verifying whether said dial pulse corresponds to said pre-test dialing digits;   wherein said delay correlativity calculator comprises: a dial pulse delayer delaying applied dial pulses at a predetermined velocity;   a first calculator receiving a first predetermined number of samples r ! among said dial pulses which are not delayed and performing a first calculation to output a result value γ1;   a second calculator receiving a second predetermined number of samples s ! among said dial pulses delayed by a first predetermined delay period and performing a second calculation to output a result value γ2;   a third calculator receiving said samples r ! and s ! and performing a third calculation to output a result value C 0  ; and   a delay correlativity determiner receiving said result values γ1, γ2 and C 0  and determining the delay correlativity of said dial pulse by performing a fourth calculation.     
     
     
       16. A dial pulse detector, comprising: a delay correlativity calculator receiving dial pulses generated by predetermined pre-test dialing digits dialed by a subscriber, and calculating a correlativity between a delayed dial pulse and an undelayed dial pulse to sample a reference signal of said dial pulse;   an energy correlativity calculator calculating an energy correlativity between said sampled reference signal and a received dial pulse, said energy correlativity calculator examining validity of said reference signal; and   a dial pulse verifier operating according to a recognition of the validity of said reference signal by said energy correlativity calculator, checking input number of times and input time of said dial pulse, and verifying whether said dial pulse corresponds to said pre-test dialing digits;   wherein said energy correlativity calculator comprises: a first buffer temporarily storing a first predetermined number of samples r' ! among successively applied dial pulses;   a second buffer temporarily storing a second predetermined number of samples s ! which are said sampled reference signals;   a first calculator receiving said samples r' ! and performing a fifth calculation to output a result value γ a  ;   a second calculator receiving said samples s !, and performing a sixth calculation to output a result value γ b  ;   a third calculator receiving said samples r ! and s !, and performing a seventh calculation to output a result value C 1  ; and   an energy correlativity determiner receiving said result values γ a , γ b  and C 1  and determining the energy correlativity by performing an eighth calculation.     
     
     
       17. A dial pulse detector, comprising: a delay correlativity calculator receiving dial pulses generated by predetermined pre-test dialing digits dialed by a subscriber, and calculating a correlativity between a delayed dial pulse and an undelayed dial pulse to sample a reference signal of said dial pulse;   an energy correlativity calculator calculating an energy correlativity between said sampled reference signal and a received dial pulse, said energy correlativity calculator examining validity of said reference signal; and   a dial pulse verifier operating according to a recognition of the validity of said reference signal by said energy correlativity calculator, checking input number of times and input time of said dial pulse, and verifying whether said dial pulse corresponds to said pre-test dialing digits;   wherein the dial pulse detector further comprises a pre-processor filtering dial pulses generated by said predetermined pre-test dialing digits dialed by said subscriber, using a dial pulse band, and sampling only a selected dial pulse for each predetermined cycle among said filtered dial pulses;   wherein said delay correlativity calculator comprises: a dial pulse delayer delaying applied dial pulses at a predetermined velocity;   a first calculator receiving a first predetermined number of samples r ! among said dial pulses which are not delayed and performing a first calculation to output a result value γ1;   a second calculator receiving a second predetermined number of samples s ! among said dial pulses which are delayed by a predetermined delay period and performing a second calculation to output a result value γ2;   a third calculator receiving said samples r ! and s ! and performing third calculation to output a result value C 0  ; and   a delay correlativity determiner receiving said result values γ1, γ2 and C 0  and determining the delay correlativity of said dial pulse by performing a fourth calculation.     
     
     
       18. A dial pulse detector, comprising: a delay correlativity calculator receiving dial pulses generated by predetermined pre-test dialing digits dialed by a subscriber, and calculating a correlativity between a delayed dial pulse and an undelayed dial pulse to sample a reference signal of said dial pulse;   an energy correlativity calculator calculating an energy correlativity between said sampled reference signal and a received dial pulse, said energy correlativity calculator examining validity of said reference signal; and   a dial pulse verifier operating according to a recognition of the validity of said reference signal by said energy correlativity calculator, checking input number of times and input time of said dial pulse, and verifying whether said dial pulse corresponds to said pre-test dialing digits;   wherein the dial pulse detector further comprises a pre-processor filtering dial pulses generated by said predetermined pre-test dialing digits dialed by said subscriber, using a dial pulse band, and sampling only a selected dial pulse for each predetermined cycle among said filtered dial pulses;   wherein said energy correlativity calculator comprises: a first buffer temporarily storing a first predetermined number of samples r' ! among successively applied dial pulses;   a second buffer temporarily storing a second predetermined number of samples s ! which are said sampled reference signals;   a first calculator receiving said samples r' !, and performing a fifth calculation to output a result value γ a  ;   a second calculator receiving said samples s !, and performing a sixth calculation to output a result value γ b  ;   a third calculator receiving said samples r ! and s ! and performing a seventh calculation to output a result value C 1  ; and   an energy correlativity determiner receiving said result values γ a , γ b  and C 1  and determining the energy correlativity by performing an eighth calculation.     
     
     
       19. A dial pulse detecting method, comprising the steps of: calculating a delay correlativity between a dial pulse generated by predetermined pre-test dialing digits dialed by a subscriber and a dial pulse delayed by a predetermined period;   sampling a reference signal of said dial pulse to obtain a sampled reference signal;   calculating an energy correlativity between said sampled reference signal and a received dial pulse by performing a cross-correlation therebetween so as to examine validity of said reference signal; and   when the validity of said reference signal is recognized in said energy correlativity calculating step, checking an input number of times and an input time of said dial pulse and then verifying whether said dial pulse corresponds to said pre-test dialing digits.   
     
     
       20. The dial pulse detecting method of claim 19, further comprising the step of: pre-processing step of filtering dial pulses generated by predetermined said pre-test dialing digits dialed by said subscriber with a dial pulse band and sampling only a selected dial pulse for each predetermined cycle among said filtered dial pulses.   
     
     
       21. The dial pulse detecting method as claimed in claim 20, wherein said pre-processing step utilizes a pre-processor comprising: a filter filtering a band of a dial pulse signal; and   a sampler sampling only each kth dial pulse among said filtered dial pulses.   
     
     
       22. The dial pulse detector as claimed in claim 21, wherein said filter is a low-pass filter suitable for removing noise contained in the dial pulses. 
     
     
       23. The dial pulse detector as claimed in claim 22, wherein said low-pass filter is a finite impulse response (FIR) filter. 
     
     
       24. The dial pulse detecting method of claim 19, wherein said energy correlativity calculating step comprises: temporarily storing a third predetermined number of samples r' ! among successively applied dial pulses;   temporarily storing a fourth predetermined number of samples s ! which are said sampled reference signals;   receiving said samples r' ! and performing calculation in the following equation (5) to output a result value γ a  ;   receiving said samples s ! and performing calculation in the following equation (6) to output a result value γ b  ;   receiving said samples r ! and s ! and performing calculation in the following equation (7) to output a result value C 1  ; and   receiving said result values γ a , γ b  and C 1  and determining the energy correlativity using the following relationship (8): ##EQU19##   
     
     
       25. The dial pulse detecting method of claim 19, wherein said delay correlativity calculating step includes providing a delay section for delaying a dial pulse to produce a delayed dial pulse, and employing said delay section in calculating said delay correlativity. 
     
     
       26. The dial pulse detecting method of claim 19, wherein said energy correlativity calculating step includes proving a plurality of multipliers for multiplying received dial pulses by sampled reference signals to obtain products, and a summer for summing the products. 
     
     
       27. A dial pulse detecting method comprising: a delay correlativity calculating step of calculating a correlativity between a dial pulse generated by predetermined pre-test dialing digits dialed by a subscriber and a dial pulse delayed by a predetermined period, and of sampling a reference signal of said dial pulse;   an energy correlativity calculating step of calculating an energy correlativity between said sampled reference signal and a received dial pulse to examine validity of said reference signal; and   a dial pulse verifying step of being operated according to a recognition of the validity of said reference signal in said energy correlativity calculating step and checking input number of times and input time of said dial pulse and verifying whether said dial pulse corresponds to said pre-test dialing digits;   said method further comprising a pre-processing step of filtering dial pulses generated by predetermined said pre-test dialing digits dialed by said subscriber with a dial pulse band and sampling only a selected dial pulse for each predetermined cycle among said filtered dial pulses;   said delay correlativity calculating step comprising: delaying applied dial pulses at a predetermined velocity;   receiving a first predetermined number of samples r ! among said dial pulses which are not delayed and performing calculation in the following equation (1) to output a result value γ1;   receiving a second predetermined number of samples s ! among said dial pulses delayed by a predetermined delay period and performing calculation in the following equation (2) to output a result value γ2;   receiving said samples r ! and s ! and performing calculation in the following equation (3) to output a result value C 0  ; and   receiving said result values γ1, γ2 and C 0  and determining the delay correlativity of said dial pulse using the following relationship (4): ##EQU20##     
     
     
       28. The dial pulse detecting method of claim 27, wherein: during said step of delaying applied dial pulses, a first-in-first-out (FIFO) type buffer is utilized.   
     
     
       29. A dial pulse detector, comprising: delay correlativity calculating means for receiving dial pulses generated by predetermined pre-test dialing digits dialed by a subscriber, and for calculating a correlativity between a delayed dial pulse and an undelayed dial pulse to sample a reference signal of said dial pulse and obtain a sampled reference signal;   energy correlativity calculating means for calculating an energy correlativity between said sampled reference signal and a received dial pulse to examine validity of said reference signal, said energy correlativity calculating means including a plurality of multipliers for multiplying received dial pulses by sampled reference signals to obtain products and a summer for summing the products; and   dial pulse verifying means operating in response to a recognition of the validity of said reference signal by said energy correlativity calculating means for checking a number of times that have been input and a time of said dial pulse that have been input, and for verifying whether said dial pulse corresponds to said pre-test dialing digits.   
     
     
       30. The dial pulse detector of claim 29, wherein said delay correlativity calculating means includes a delay section for delaying a dial pulse to obtain the delayed dial pulse.